More particularly, the invention relates to a track support of the track support type of an electric power supply system via the ground for a land vehicle, notably a tram, as a profile in an electrically insulated material, comprising: a substantially planar upper surface, provided with a longitudinal flute intended to receive a track segment, and with a longitudinal groove intended to receive a low voltage electric power supply cable; and a lower surface intended to bear upon a base for maintaining the support in the roadway.
A system for an electric power supply via the ground consists of a plurality of rails connected longitudinally to each other via junction casings.
Each rail includes an electric power supply track support and an electric power supply track, which is formed by a plurality of conductive segments longitudinally separated from each other by insulating segments.
Document FR 2 938 800 describes a track support assuming the shape of a honeycombed profile in glass fibers, comprising a substantially planar upper face, provided with a single longitudinal flute intended for receiving the segments of the track, and a planar lower face intended to bear upon the ground. The profile includes a core connecting the upper face to the lower face which is provided with at least one longitudinal power supply conduit, able to receive a low/high voltage power line intended to be connected to the conductive segments for bringing them to a potential suitable for the needs of the vehicle. The flute and the power supply conduit of a profile are positioned in a central and symmetrical way with respect to a longitudinal middle plane of the support perpendicular to the upper face of the latter.
For the case of a tramway, such a support has a length of about 11 m.
The method for implanting such a support consists of making a trench in the roadway to be equipped with such a system for supplying power via the ground. Once the trench has been cleared, a concrete apron is cast, in order to form a planar surface at the bottom of the trench. The track supports are then positioned on metal saddles attached to the apron. Next, an iron stringer is cast below and on the sides of the track support in order to guarantee its anchoring in the roadway.
The supports are mechanically connected two by two by a junction casing essentially formed by a pair of splice bars, on either side of the longitudinal axis of the supports and a metal hood obturating the junction casing from the top.
The power supply cable is placed in the central conduit of the supports and connected to a conductive segment. Finally the different insulating and conductive segments are attached in the flute of the profile.
The insulating segments are attached by adhesive bonding while the conductive segments are attached by adhesive bonding and screwing onto a support.
Such a support has different problems.
A first problem is related to the maintenance of the system. In the case of an operational accident or quite simply in the case of wear of different components of a rail, it is necessary to replace this component.
If this is replacement of a segment, in particular of a conductive segment, the latter being attached by adhesive bonding and screwing to the support, detachment of the segment of the support often leads to degradation of the actual support.
The replacement of the support is extremely complex. This means breaking the concrete stringer in order to expose the saddles for attaching the support to be replaced. Next, this means resuming the different installation steps mentioned above for installing the new support.
Such a maintenance operation necessarily takes a lot of time (about 1 month). It will be understood that, when this means carrying out a maintenance operation at busy crossroads, within a city for example, it is therefore necessary to reduce the intervention time.
A second problem lies in the robustness of the support. In practice it is found that a honeycombed profile and in glass fibers has insufficient mechanical strength.
A third problem is related to the making of curves.
In a one-piece version of the track support, the latter may be slightly bent so as to have a radius of curvature greater than or equal to 95 m. A one-piece support cannot be further bent.
However, such a support has to be bent at the factory and then provided on the installation site.
In order to produce curves having a smaller radius of curvature, a multi-piece version of the support shown above has been proposed. According to this version, the core of the support is subdivided into three narrower sections, along two sectional planes parallel to the middle plane of the support. Each section of the support may be bent with a radius of curvature of less than 95 m in order to obtain radii of curvature as small as the turning radius of the vehicle using the power supply system. For a tram, the turning radius is of about 18 meters.
However, these three sections of the support have to be bent at the factory and also attached together at the factory, before the thereby made support is provided on the installation site.
One understands the logistic problems encountered during the installation of such a support.
The object of the invention is therefore to overcome these problems by notably proposing a support able to be easily detached from its concrete base and which has increased robustness.
The object of the invention is a track support of the aforementioned type, characterized in that the lower surface is curved, preferably V-shaped, so that the support is convex so as to be, at least transversely, maintained in a recess with a mating shape, made in the base for maintaining the support in the roadway.
According to advantageous but not mandatory aspects of the invention, such a support may incorporate one or several of the following features, taken in any technically admissible combination:    the lower surface of the support is crenellated along a longitudinal direction of the profile formed by the support so as to be, at least longitudinally, maintained in the recess of the mating shape, made in the base.    the lower surface comprises transverse offsets participating in maintaining the support in position in the recess.    the support is made in one piece of material, and in that the support is in an elastomeric material so that the support is elastically deformable.    side edges of the support, connecting the lower surface and the upper surface are provided with through-holes for inserting pins allowing direct attachment of the support on the base.    a bottom of the flute is in communication with the groove, and edges of the bottom of the flute, located on either side of the groove are provided with recesses for accommodating means for attaching a segment on said support.    each sidewall of the groove includes a lateral passage opening into an associated recess of the bottom of the flute, in order to allow the setting into place of a gib at the bottom of said recess in order to receive a bolt by screwing, allowing attachment of a segment on said support.    the upper surface includes side faces, positioned on either side of the groove, each of the faces being tilted so as to have a tilt angle b relatively to a horizontal plane, the tilt angle having a value between 0 and 4°, notably 2°.    each lateral face of the upper surface of the support includes a pattern promoting water flow, and adherence to the support.    each lateral edge of the support is provided with a channel extending longitudinally through the support and connecting together both transverse end faces of the support, said channel being intended to receive an antenna cable.    the support has a reduced length and the groove forms a cavity, each transverse end face being provided with an orifice opening into the cavity capable of receiving the end of a tube for bringing a low voltage power supply cable and/or an antenna cable.    each lateral edge of the support being provided with a channel extending with an angle so as to connect a transverse end lateral face of the support to a sidewall of the groove for circulating an antenna cable.
The object of the invention is also a method for implanting a support compliant with the previous support, characterized in that it includes the steps: clearing a trench in a roadway; casting a concrete apron; positioning the support by means of a template, the support being provided with anchoring dowel pins placed in the through-holes with which the lateral edges of the support are provided, the support being optionally stressed so as to give it a suitable radius of curvature; casting a concrete base substantially up to the height of the upper face of the support; attaching by screwing, through the through-holes, the support to the base for maintaining the support in the roadway.
The object of the invention is also a rail of a system for supplying power via the ground, characterized in that it includes a plurality of supports positioned end to end on a concrete base for maintaining said supports in the roadway, each support being a support compliant with the previous support, and a plurality of conductive and insulating segments, two successive conductive segments being separated from each other by at least one insulating segment, the segments forming together the track and being received in the flutes of the supports.
Preferably, two successive supports are secured to each other by means of a junction sheet shaped so as to have a shape mating that of the lower surfaces of the supports to be connected and able to avoid possible electric leakages.
The object of the invention is also a method for implanting a rail compliant with the previous rail, characterized in that it includes the steps: clearing a trench in a roadway; casting a concrete apron; by means of a template, positioning the different constitutive supports of a rail section and the tube for bringing the antenna and low voltage power supply cables, the supports being provided with anchoring dowel pins placed in the through-holes with which the lateral edges of each support are provided, the supports being optionally stressed so as to give them a suitable radius of curvature; casting a concrete base substantially up to the height of the upper face of the supports; having the antenna cable circulate in the channels of the supports and connecting the low voltage power supply cable to the conductive segment of the rail section; attaching by bolting the conductive segments and the insulating segments of the track of the rail section in the flutes of the various supports.